Terminal velocity of a copper ball of radius 2 mm through a tank of oil at 20^(@)C is 6.0 cm/s. Compare coefficient of viscosity of oil. Given p_(cu) = 8.9 xx103 kg//m^(3), rho_(oil) = 1.5 xx 103 kg//m^(3).

Terminal velocity of a copper ball of radius 2 mm through a tank of oi

1.	Terminal velocity of a copper ball of radius 2 mm through a tank of oil at 20^(@)C is 6.0 cm/s. Compare coefficient of viscosity of oil. Given p_(cu) = 8.9 xx103 kg//m^(3), rho_(oil) = 1.5 xx 103 kg//m^(3).
Answer» Solution :`nu_(t)=(2)/(9)[(G(sigma-rho)r^(2))/(eta)]` `eta=(2)/(9)[(9.8xx(8.9xx10^(3)-1.5xx10^(3))(2XX10^(3))(2xx10^(-3))^(2))/(6xx10^(-2))]` `=1.08kgm^(-1)s^(-1)`